Too often we model the parts without noticing the default units setting in Creo. Whenever we start a new session in Creo / pro Engineer, the default units setting is Inch lbm Second.
Inch is the widely used customary unit in USA, CANADA and UK. On the other hand, millimeter (mm), a SI unit is accepted as a dimensioning standard internationally.
The units can be changed at any time i.e at the beginning of a part modelling / sketching or after you fully complete the model or at any time inbetween.
Proper / correct Units are important for defining the properties of the parts which will be used in mass calculations, kinematics and simulations, design calculations, production drawing release and most importantly for production communication . Choosing the incorrect units will impact the cost if unnoticed during design phase and design trails.
For this reason, almost all companies have their own config.pro setting file which will be used in all the work we do in creo parametric.
I will explain 3 methods to change the units in this article. Lets see one by one.
- Change the default unit setting for an empty template
- Choose an inbuilt template for Units.
- Change the units of a already created part / assembly.
In methods 1 and 2, you have to edit and save the config.pro file. Creo looks for the config.pro file in the following locations and in the following order.
- <creo_loadpoint>\Common Files\<datacode>\text (creo_loadpoint is the Creo Parametric installation directory) – This is where companies keep their cofig.pro files usually so that all models / drawings are made using company standards.
- Login directory – This is the home directory for your login ID. This is also controlled by the company and keeping the configuration file here lets you start Creo from any directory without having a copy of the files in each directory.
- Startup directory – This is your current or working directory when you start Creo.
If you want to change the default unit setting, You can modify the below config.pro settings and save it in your machine.
Below is the settings that you can change to make it as default. Please note that you have to keep this config.pro in any one of the directories mentioned above so that Creo reads the config.pro file at startup.
|Configuration option||English Unit Setting||Metric Unit Setting|
file_open_default_folder is the config.pro option that will setup the default working directory.
Note that the changing the above options will only work in an empty template. See the image below. You have to uncheck the “Use default template” and select empty template from dropdown. In this case, you have to start from the very beginning.
In this method, We will change the default unit template instead if the unit itself. For each type of part i.e Part modelling, sheetmetal, eCAD, Drawings, assembly etc., you can browse and select the default template and save the config.pro file in the location mentioned earlier.
To change the default template of a solid part, click the setting and click on browse from dropdown and select the suitable template from the folder location shown below. For example, I filtered mmks templates using search option on the top of the window. From here, you can select the solid_part_mmks_abs.prt or any other desired one.
After this setting, you can use the “Use default template” and still have the newly configured units.
This method is for changing the units for an already created model / assembly or for the models you are currently working. Below is an example.
To change the units, Go to File -> Prepare->Model Properties and then from the model properties windows, click on Change in units. See image.
You will now see the current unit of the model. In this case, it is Inch lbm Second.
To change this to millimeter Kilogram Sec (mmKs), Select the mmKs from the list and click on Set. You will now get a popup window asking for how do you want to make this change.
If you choose the first option, then 1 inch becomes 25.4mm in your model since your previous model was using Inch as units. In this case, the new dimensions of the part is shown below and all dimensions are in mm now.
If you choose the second option, then the number values remain same but only the units are changes. That means 100 inches will be changed to 100 mm.
Use the same methods to change the units of an assembly. But in the assembly only the assembled dimensions are affected. The parts used in inside the assembly will still have their own units in which they were modelled.
That’s all for this topic. I hope you found this useful. Thanks.
Time needed: 1 minute.
How to change UNITS in CREO
- Go to File -> Prepare -> Model Properties
This opens the Model Properties editor
- Click on the “Change” button under UNITS
This opens the UNITS dialog box where you can select from already existing combination or create a new one.
- Select the desired UNIT SYSTEM from the list
Choose the system of unit and click on SET
- Choose how you want to interpret the existing dimensions
Choose from two options, either keep the same value and change the units alone or convert the values to the new units.